Improvement in low-water indicators



mi tateaatwi may GEORGEM. HOPKINS,- Or ALBION', NEW YORK.V

v Letters .Patent No. 87,102, dated Fatwa/ry 23, 1869.

IMPROVEMENT IN LOW-WATER INDICATORS.

B e it known that I, GEORGE M. HOPKINS, of Albion,

in the county of Orleans, and State of New York, have invented a new and useful Improvement in Low-WVater Indicators for Boilers; and I do hereby declare that the following is a full, clear, and exact description of the construction and operation of the same, reference being had to the annexed drawings, makinga part of this specification, in which- Figure 1 represents avertical section.

Figures 2 and 3 represent modifications of a portion of the same.

The object of this invention is to provide an apparatus which is to be connected with a boiler at a given line, which shall alarm whenever the water in the boiler passes below said line.

I will proceed to describe my invention.

In the accompanying drawings, (see fig. 1)-

vA is a tube, which is provided at its upper end with a valve-seat, I3, to which is fitted the valve O.

D is a rod, extending through the valve G, and engaging with the stirrup E, by means of a screw cut upon its lower end.

F is a wire or strip of brass, or other expansive metal, the upper end of which is connected with the stirrup E, while the lower end is attached in any convenient manner to the tube A at G. A

. H is a cap, fitted to the upper end of the tubef'A, which covers the valve C, and its seat B, and is provided with an opening, I, connecting with the Whistle J.

The rod D passes upward through the cap H, and is provided with a suitable head, K, beneath which is placed the spring L, the' lower end of which rests upon the cap H.

M is a support for the thumb-screw N, placed immediately over the rod D.

The valve C is held firmly to its seat B by the wire F, upon which tension is produced, by turning the head K, operating the screw in the stirrup E.

The stirrup Fr is prevented from turning by the pins a a.

If it is desired to shorten the apparatus, it may be accomplished by passing the wire, or strip F, around the pulley 0, as shown in tig. 2, or in place of the pulley O, the wire may be cut, and connected by means ofthe lever P, as in iig. 3.

By multiplying the pulleys or levers, the apparatus may be shortened as much as is desired. In such case the end, G, ofthe wire, or strip F, may be attached at 4any desirable point.

The apparatus is connected to the boiler just above the line at which an alarm is desired.

The operation is as follows: As long as the water in the boiler covers tue end of the tube A, the water,l in the tube will remain comparatively cool. When the water drops below the end of' tube A, the water passes out of it and steam enters The temperature being thereby increased, the wire F expands, releasing the valve O, when the combined forcef'of the spring L andthe steam, opens the yalve C, permitting the escape of the steam through the whistle J, causing an alarm.

When the apparatus has alarmed, the valve C may be forced down to its seat by means of the screw N. `When the water in the boiler again covers the mouth of the tube A, the water is forced into it, and there beingno circulation, it soon cools, and, when cool, the wire F is contracted, and the screw N should be loosened.

I am aware that expansion-rods have been used for the purpose of opening a valve for an alarm; therefore I do not desire to claim the opening of the valve by the expansion of the wire; but

What I do claim as my invention, and desire to secure by Letters Patent, is l 1. The Wire, or strip F, in combination with the stirrup E, rod D, and tube A, substantially as set forth.

2. The arrangement of valve C, rod D, stirrup E, and springL, substantially as shown and described.

3. The screw N, in combination with the above devices, as set forth. A y

Signed by me, this 11th day of December, 1868.

GEO. M. HOPKINS.

Witnesses:

JOHN A. STRAIGHT, W.- P. MORGAN, Jr. 

